Okay, here is another odd little study from the Brits (British that is, not Spears) that was in The Telegraph:

Bird populations in urban areas of Britain are directly affected by the wealth of residents, scientists say.

They discovered there are more birds in affluent urban areas than in poorer ones because wealthier people are more interested in birds and more inclined to feed them.

Scientists say they have discovered that a high density of bird feeders and bird tables raises the overall numbers of birds in urban areas, independently of factors such as the presence of parks and large gardens.

However, the "bird feeder effect" found by researchers from Sheffield University varied markedly according to the social and economic status of the households in the area.

The study found that both affluent suburbs within the Sheffield city boundary and sought-after areas close to the city centre had far more birds than deprived wards, where bird feeding was less common, possibly because it would dent family incomes.

The researchers included some of the richest and the poorest wards in Britain.

The study, published in the journal Diversity and Distributions, says bird feeding had no effect on the range of birds, only on the populations of species, such as blue tits, great tits and coal tits, commonly attracted to bird feeders.

It has been estimated that 60,000 tons of food a year are left out for birds in Britain.